I Started Noticing A Rash Type Looking Things On My

I started noticing a rash type looking things on my legs which I didn't think too much about because I have had some skin cancer's turned off but leave red marks but he seemed to spread to the back of my legs and then on my armI was starting to be concerned that might be shingles which I had ones are I don't really know I am concerned because we are supposed to go on a two-week vacation starting Saturday